So for the last couple of years I've been using an old Vistalite casing that holds a 6v 10 watt halogen screw bulb with a lead acid battery.

It's worked great and people have told me they thought I was on a motorcycle when they saw me on the road, but the bulb's now burnt out.

I've been looking for a replacement and nobody seem to have one.

Everything is switching to LEDs, so I was wondering if I could use an LED with my old battery.

In the meantime, I'm using a BLT LED white blinky, but it's a bit old and lately, the switch has been changing on it's own. When I hit a bump on the road, it switches from blinking mode to steady mode. I just press the button again and it goes back to blinking

LED output per watt is so much better than any halogen, it would be well worth the time to look into it. I haven't seen many 6V LEDs out there, but I'm sure there are some. You might want to look at bulbs made for hub generators, they usually run 6V. From personal experience, a 4W LED is brighter than a 35W halogen given the same pattern. It's a huge difference.

A MagicShine head might work fine on a 6v battery. It's designed to run on a nominal 7.4 volt LiIon cell. When I get home I'll see about hooking up 6 volts worth of NiMHs or something and see how it does on them.

A MagicShine head should draw less than the 10 watt halogen and mine puts out WAY more light than the overvoltaged 12v/20 watt halogen that I used to run. Hardly even a comparison really. People think I'm a car with a headlight burned out.